Three of the London Bridge attackers have been named by Scotland Yard.
Khuram Shazad Butt, Rachid Redouane and Youssef Zaghba, who lived in east London, killed eight people and injured dozens more during the 3 June terror attack.
All three were shot dead by armed officers within eight minutes of the first emergency call being made.
- Khuram Shazad Butt
Khuram Shazad Butt was a British citizen born in Pakistan.
The 27-year-old had been known to security services since 2015 - but police said there was no evidence any attack was being planned.
This was despite friends and neighbours reporting him over fears he was becoming increasingly radicalised.
Butt even featured in a Channel 4 documentary broadcast last year called 'The Jihadis Next Door'.
He is also alleged to have been an associate of hate preacher Anjem Choudary.
Mohammed Shafiq, chief executive of the Ramadhan Foundation, said Butt called him a "Murtad" - traitor in Arabic - when he confronted Choudary about his support of terrorism days after the murder of soldier Lee Rigby in 2013.
The Jabir Bin Zayid Islamic Centre, where Butt occasionally worshipped, said "some years ago after interrupting a Friday sermon he was asked to leave the mosque".
He was also reported to counter-terrorism authorities almost a year ago following a "violent scuffle" with a member of anti-extremism organisation Quilliam Foundation.
Residents at a block of flats in Barking, east London - where a number of arrests were made - said Butt had lived in the area for around three years.
He was known locally as "Abs/z" and was identified by neighbours as the terrorist in a photo which showed him crumpled on the ground after being shot by armed police.
Butt was father to a toddler and baby and a keen gym-goer and weightlifter, neighbours said.
"I knew Abz and the kids. They were normal. Their kids played with the other kids," neighbour Bona Mapianda.
"We talked about football, he didn't have a team but he followed the game.
"Terrorism is so extremist - you don't imagine it would be your neighbour next door."
Transport for London (TfL) confirmed Butt worked for London Underground for just under six months as a trainee customer services assistant, leaving in October last year.
A picture published in The Daily Mail reportedly shows him at West Kensington station, wearing an orange high-visibility jacket and blue uniform.
- Rachid Redouane
Mr Redouane, 30, who claimed to be of Moroccan and Libyan origin, was also living in Barking.
He used the name Rachid Elkhdar and claimed to be six years younger than he was - but was not known to authorities.
He was found with an Irish ID card on his body after being killed by police.
The terrorist was married to an Irish woman, reportedly named as Charisse O'Leary, 38, and the pair have a 17-month-old daughter together.
Security sources in Ireland confirmed he married there in 2012 and lived in Rathmines, Dublin.
It is not clear when he came to the Republic or how long he stayed, but it is believed he used Irish jurisdiction to get a European Union permit which allowed him to be in the UK.
Redouane left Ireland after getting married and may have travelled to Morocco before settling in the UK.
He returned to Ireland again in 2015, again for an unknown length of time, but Taoiseach Enda Kenny said he was not one of a small number of radicals under surveillance.
Redouane was a former pastry chef, according to reports.
- Youssef Zaghba
The third London Bridge attacker has been named by Italian media as Moroccan-Italian Youssef Zaghba.
Italian newspaper Corriere Della Sera said he has an Italian mother who lives in Bologna and a Moroccan father.
The paper reported he was born in Fez in Morocco and had seasonal work in a London restaurant.
It reported he was stopped by Italian police in March 2016 at Bologna's airport trying to fly to Turkey and then on to Syria.
Italian intelligence officials reportedly communicated this to their UK counterparts.
The name emerged as MI5 and police faced questions after it emerged one of the three perpetrators, Khuram Shazad Butt, 27, had been investigated two years before the atrocity.
- Police appeal for more information
Assistant Commissioner Mark Rowley has appealed for anyone with information to contact police.
He said: "I would urge anyone with information about these men, their movements in the days and hours before the attack and the places they frequented to come forward.
"Work is ongoing to understand more about them, their connections and whether they were assisted or supported by anyone else", he added.
Mr Rowley claimed police are currently investigating 500 terror cases involving 3,000 "subjects of interest" after quizzing 20,000 individuals.
He added: "The security and intelligence services and police have stopped 18 plots since 2013, including five since the Westminster attack two months ago.
"We would urge the public to be vigilant and to report any suspicious activity to the police by calling us in confidence on 0800 789321 or in an emergency calling 999."
ITV News Security Editor Rohit Kachroo said: "Rarely in recent years have plots been foiled, but never in that time have so many got through".